How Old Is Your Cat in Human Years?
Convert cat years to human years. Indoor and outdoor cats age at different rates.
Cat Aging Is Front-Loaded
Cats reach adulthood quickly — a 1-year-old cat is roughly equivalent to a 15-year-old human. By age 2, a cat is about 24 in human years. After that, each cat year equals approximately 4 human years. This means a 10-year-old cat is about 56 in human years — solidly middle-aged.
Indoor vs Outdoor Lifespan
The difference is dramatic: indoor cats live 15-20 years on average, while outdoor cats average 5-10 years. The gap is due to traffic, predators, disease exposure, fighting, and environmental hazards. Indoor/outdoor cats fall in between at 12-15 years. This is the single biggest factor in cat lifespan.
Indoor cats have doubled in average lifespan over the past 30 years — from 7-8 years in the 1990s to 15-17 years today. Better nutrition, veterinary care, and the trend toward keeping cats indoors are the primary drivers.
